Ford Ranger Radiator Issues

Hey there. I have a 2002 Ranger xlt 2.3 5speed and in the spring i ended up replacing the thermostat, housing and hoses. The truck has run like a champ. The past couple of weeks I have the issue with the temp guaging rising until it nearly hits the overheating mark but before it does, it mysteriously drops down rapidly to the normal level and this process keeps repeating itself every time i drive it.

My bad on the new thread. I will have to feign "newbieness" to any type of forum like this. I wasnt even aware something like this was avail. online until it was mentioned in passing. Now I know how these forums work. I DO however, appreciate your reply with your experience.

I find that unlike the repair manuals say the heater hose and lower radiator hose attach to a approx 8" pipe that inserts into the pump body. This pipe runs behind the belt tensioner and through the generator bracket. There is a brace welded to this pipe that bolts to the generator bracket. To remove the pump this pipe must be pulled out of the pump body from underneath the truck OR the generator and everthing assoc with the genrator bracket and belt tensioner must be removed so the pump with the pipe still attached can be removed. The question is "What holds the pipe in the pump body?" Is it just permatex or is it pressed on? HELP before I break something. Thanks

If no heat from the heater, the themostat is probably stuck open. A new one should fix this.

For the best milage, and best 'wear' on the motor, the correct, functioning themostat should be in the truck. The motor need to warm up to the expected temperature for the oil to do it's best work, and the best milage. Don't continue to run a vehicle with no themostat or one stuck open. It's not fatal, but does no good to the truck.

yes the heater does get warm i get really hot heat not right away but like normal so u think its the wiring or something like that. should i have it fixed is it expensive to get it fixed or not worry about it

the factory thermostat is 160 degree and shows on the gauge as cold ,,, this will allow the engine to run rich which means less mpg I ve ran into this on many ford ranger and mini vans replace the thermostat with a minimum of 180 degree and you will see better mpg and over all performance you may want to check the 02 scencers for proper operation at the same time.

the factory thermostat is 160 degree and shows on the gauge as cold ,,, this will allow the engine to run rich which means less mpg I've ran into this on many ford ranger and mini vans. replace the thermostat with a minimum of 180 degree and you will see better mpg and over all performance you may want to check the 02 sencers for proper operation at the same time.

I have replace the thermostat, flushed it 3 times, radiator cap, and still the system builds pressure while driving to blow the lid off the reserve tank. The temp gauge will be normal then start going in reverse to the cold side and at that point it blows the lid off the reserve tank and sprays coolant all over. Does anyone have an idea why it is doing this please?

This Is happing to my truck too......everybody saying things to do.....and I have done everything they are saying and still the system builds pressure while driving and blowing the lid off the reserve tank. The temp gauge will be normal then start going in reverse to the cold side. I get warm heat. I need someone that had this happen to them and fixed It. I mean no offence to anybody but this in gonna cost me my truck. I'm gonna dump It, but I like it alot. H.E.L.P. Please......Phil @ printman716@aol.com

I'm at my wits end! Does anybody know what the .... going on with this truck? I replaced everything, the cap, thermostat, control knobs, hoses, flushed 3 times, and still temp gauge goes up and down and no heat, it used to build pressure and back out the tank but that stopped. I found the Consumer Guide Review on this and this is what it says to do. Question Is did anybody have this problem and fixed It!?!?

Accessory belt: Squealing serpentine drive belt due to faulty water pump pulley on 4.6L V6 engine. (2001)Air conditioner: The air-conditioner hose may rub against the radiator hose and one, or both, developleaks. (1998)Audio system: The in-tank fuel pump causes a whining or buzzing noise to come through the radiospeakers. (1998-99)Battery: The battery tray may have burrs that cut into the battery causing it to leak and eventually fail.(1998)Engine misfire: Hesitation or surging when accelerating is caused by a faulty mass airflow sensor. (1998-99)Engine misfire: The truck may feel like it is thumping or jerking under acceleration due to a problem withthe driveshaft requiring replacement. (1998-99)Heater core: Installing a restrictor in the heater inlet hose may repair heater cores leaks. (1998-2002)Timing belt: The timing chain on 4.0-liter V6 may make noise in hard acceleration. A repair kit is available.(1999-2000)Transmission problems: Transmission flare when shifting from 2nd to 3rd gear is due to shift solenoidmalfunction. (1998-2001)Vehicle noise: A hammering noise occurs due to steam forming in the cooling system requiring a coolant bypassretrofit kit. (1998-00)Please let me know....Phil

Phil.. did you ever figure out what the problem was? I'm having a similar problem. I have 99 ranger 3.0. I had my coolent system flushed and a new thermostat put in about 3 years ago. Nothing wrong with the old one, just wanted a new one put in. I put the same type thermostat in that came out of it.. 195 or 197. Afterwords, my temp gauge would not get up to normal operating temperature like it used to and would fluctuate about a third of the way up. My heater still blowed out good heat though. Afterwords I noticed my mpg dropped from an average of 21mpg to 18mpg. Well, It was time to service my truck again and I told the mechanic to go ahead and put another thermostat in to see if that was the problem (195). He did and now the temp gauge runs even lower than what it did before, just above cold. I still have good heat though. He said it could possible be something with the Temp Sending Unit or the Temp Sensor. According to Haynes Repair manual, the Sending Unit controls the temp gauge and check engine light on the instrument panel. The Temp Sensor is used by the computer to determine engine coolant temp and adjust fuel/air mixture. Both sensor and sending unit are screwed in on the thermostat housing. This is why I think my gas millage is suffering because of a cold reading. A cold engine or a cold reading makes the computer stay in Open Loop (Rich Mixture) output that can hurt mpg and emissions. But I don't understand how can replacing the same temp thermostat that came out of it cause the temp gauge to show a colder reading? My theory is that an air bubble gets lodged in the housing after replacing the thermostat and refilling the coolant causing an inaccurate reading from the sending unit... That's all I can figure out. I'm gonna have to do something because my mpg is sucking big time! I'm gonna replace the temp sending unit and temp sensor and see if that does it. I don't know what else to do.

Mycoolant backs into the reserve tank and will not return into the radiator.I think some of the coolant blows out of the top of the reserve tank as well. I removed the thremostat and nothing changed. Can any one help me? my email is : inspect@sonic.net

2) To get coolant back into the radiator from the overflow tank, the rubber line from the top of the radiator to the overflow has to be air tight. No cracks, etc. If it is not airtight, air is pulled back into the radiator, not coolant from the tank. Also, the radiator cap has to be working correctly. It basically has a two-way valve in the top of it. If the radiator overheats, the pressure goes up and at a certain pressure the valve opens and coolant flow thru the rad cap, thru the rubber tube, into the overflow. When the rad cools down, the creates a partial vacumn in the rad which opens the valve in the cap in the opposite direction, allowing coolant to be 'sucked' back into the radiator from the overflow tank.

So, you can see that the radiator cap, it's valve, must be working correctly and there can be no air leaks in the rad cap seal to the radiator and in the rubber hose to the overflow tank. And, in the overflow tank, there is a tube that goes almost to the bottom of the tank. It must be in place, and the hose connection to the top of this tube must not leak, so the coolant will be pulled back into the radiator.

Oh, and all the other rubber lines in the cooling system must be air tight. If you have a small leak in any of them, rad hoses, heater hoses, etc, then when a motor cools down, air will be pulled into the system at the leak, and it will not form the vacumn to pull coolant back from the overflow tank.

As a matter of fact, you might have a head gasket leak. This causes a motor to overheat significantly, which would blow coolant into overflow. But with a bad gasket leak, air could be pulled back thru the gasket and coolant not be pulled out of the overflow.

Basically, if the truck is overheating, you need to work on that first. If it's a head gasket, this is big money to fix.

I have a 96 2.3 4 cyl and i cannot find the sending unit my temp gauge pegs out hot always but the truck never runs hot so I am assuming sending unit gauge or connection is bad but I cannot find the sending unit. All suggestions and info will be appreciated.

check at or very near the thermostat. it is not part of multiwire harness. should be a single wire lead to the sending unit. once you "think" you have it located, disconnect it and see if the temp gauge goes to zero.

We are having the same problem described with the overflow tank blowing open and spraying coolant all over, We tried replacing the temp sending unit and sensor but still having the same problem. We are going to try replacing the waterpump next, Has anyone found a solution to this problem? delwood96@yahoo.com

i have an 98 ranger with a 4.0 when i turn on the heater my temp gauge will go up and down.i have redone the heads and clean the radiater to and a new t-stat.my heater valve is leaking a little and i belive its pulling in air with the heater on.the truck never gets hot.with the heater off its fine.

my truck has a plastic heater valve ,it was leaking a little around the shaft with tthe heater on.it was sucking air and making air pockets and when the air would hit the sencer for the gauge it would go down and when it passed and the nwater came back the gauge would go up.i replaced the heater valve and since i did that it has been ok.

I have a 1998 3.0l Ranger and cannot figure the coolant problem out. The heating system worked fine until I flushed it last year. SInce then, I have replaced the thermostat twice, the second time with a quality replacement part, bled the air out of the system, replaced the rad cap, and that hasn't worked.The symptoms are: coolant goes to reservoir but will not return. When I tried to get the air out, I followed protocol, but upon opening the throttle to 2000 rpm and completing the fill, the rad fluid just gushes out the open rad neck. I get heat upon initially running the engine, but once the fluid is kicked into the reservoir, heat ceases. The temperature gauge never goes above 1/2 way, and it is not over heating. I do smell coolant in the cab, but not sure if it's just from the top popping off the reservoir. The exhaust has been noticeably thicker and whiter, and no coolant leaks can be detected other than the reservoir overflow.Both upper and lower hoses are warm when running, and the water pump does make a ticking noise when running. Please tell me it is either a water pump or even a heater core, not a head gasket. I'm not sure........